Fin-stabilized subcaliber projectile

ABSTRACT

A fin-stabilized subcaliber projectile, which comprises a projectile body including a central portion. A drive cage surrounds the central portion of the projectile body. The drive cage includes a plurality of segments held together by suitable means and covered by a common sealing disc on its rear side. The sealing disc lies in front of a guide or fin assembly arranged at the rear. The rear of the drive cage is formed as a frustocone, and the sealing disc on the rear side is shaped such that as a result of gas pressure developed upon firing, the drive-cage segments are pushed with radial force against the projectile body.

United States Patent 1 Luther et al.

[ 1 Aug. 19, 1975 l FIN-STABILIZED SUBCALIBER PROJECTILE [73] Assignee: Rheinmetall GmbH, Dusseldorf,

Germany 22 Filed: July 17,1973

21 Appl. No.: 379,970

[30] Foreign Application Priority Data July 22, 1972 Germany 2236142 [52] U.S. Cl. 102/93 [51] Int. Cl. F42b 31/00; F42b 13/16 {58] Field of Search 102/93 [56] References Cited UNITED STATES PATENTS 3,000,316 9/1961 Dunlap et a]. 102/93 3,125,957 3/1964 Lipinski 102/93 3,430,571 3/1969 Barr [02/93 3,620,167 11/1971 Romer et a1. 102/93 FOREIGN PATENTS OR APPLICATIONS 143,675 1/1954 Sweden 102/93 Primary Examiner-Benjamin A. Borchelt Assistant ExaminerC. T. Jordan Attorney, Agent, or FirmErnest G. Montague; Karl F. Ross; Herbert Dubno [57] ABSTRACT A fin-stabilized subcaliber projectile, which comprises a projectile body including a central portion. A drive cage surrounds the central portion of the projectile body. The drive cage includes a plurality of segments held together by suitable means and covered by a common sealing disc on its rear side. The sealing disc lies in front of a guide or fin assembly arranged at the rear. The rear of the drive cage is formed as a frustocone, and the sealing disc on the rear side is shaped such that as a result of gas pressure developed upon firing, the drive-cage segments are pushed with radial force against the projectile body.

1 Claim, 2 Drawing Figures Illlllllll llllllllllllllllllll PATENTEU AUG! 9 ms II/I/I/I/I/I7IL/ III FIG.

FIN-STABILIZED SUBCALIBER PROJECTILE The present invention relates to a fin-stabilized subcaliber projectile having a drive cage, surrounding the body of the projectile in its center region, said cage consisting of a plurality of segments which are held together by suitable means and are covered by a common sealing disk at the rear, the disk in its turn lying in front of the guide or fin assembly arranged at the rear (see U.S. Pat. No. 3,620,167).

The drive cage is of such a nature that the drive-cage segments, after the emergence of the projectile from the barrel, can loosen and detach themselves from the body of the projectile, so that they are positively cast out of the path of the fin mechanism which extends far beyond the diameter of the projectile body.

In the previously employed weapons, which operate with an operational gas pressure of, for instance, max. 4500 atm. with a caliber of 105 mm, the drive cage in accordance with the present invention represents an optimum solution to problems which may arise.

Since in future weapons, inter alia, there is the requirement of higher operational gas pressures, subcaliber projectiles with the proven drive cages have been shot with a gas pressure substantially exceeding the maximum pressure.

In this connection it has now been found that the gas penetrates into the joints of the drive-cage segments and presses them although only slightly outward against the wall of the barrel. Thus the gas effects erosion between the drive-cage segments and particularly on the thread of the projectile body, so that an exact transmission of power from the drive cage to the body of the projectile can no longer be assured. The result is that the projectile does not reach its predicted target.

It is an object of the present invention to provide a fin-stabilized subcaliber projectile, while avoiding the mentioned disadvantages, the projectile includes a drive cage which is suitable to receive and transmit high gas pressures to the body of the projectile.

It is another object of the present invention to provide a fin-stabilized subcaliber projectile, i.e. of the type of U.S. Pat. No. 3,620,167, which in the rear of the drive cage is constructed as a cone and the sealing disk on the rear side is provided with a corresponding development in such a manner that as a result of the gas pressure, which is developed upon firing, the drivecage segments are acted on with a radial pressing pressure against the body of the projectile.

These and other objects will become more readily apparent from the following detailed description of the present invention, reference being made to the accompanying drawing, in which: FIG. 1 is a section through the drive cage in accordance with the present invention; and

FIG. 2 is an elevational view, partly broken away.

Referring now to the drawing, the drive cage 1 is divided into several segments so that the cage as long as the projectile body 2 provided with the guide or fin assembly 2' is in the barrel is firmly connected with the body of the projectile by transmission means 4, which are force-locked in the axial direction, in the form of a thread or of grooves. The segments are held together on the outside by at least one ring-shaped band 5.

The rear of the drive cage 1 is designed substantially as a cone 1d (i.e. is frusto-conically forwardly divergent) and is so stepped in direction towards the body of the projectile 2 and also the circumferential surface, as to give rise to two perpendicular annular surfaces 1e and l f. The sealing disk 7a is now placed over the cone 1d, as well as the annular surfaces 1e and If and fastened by screws 10 to the drive cage 1. The sealing disk 7a can be connected with the drive cage also additionally or solely by an adhesive. In the case of screw fastening, it is advisable to increase the application force of the screw 10 by interposing a washer 11. Of course it is possible within the scope of the present invention for the sealing disk 7a and the ring-shaped band 5 to consist of a single piece.

The manner of operation is as follows:

The gas pressure developed upon firing can be resolved into an axial force and a radial force. The radial force causes the drive cage 1 to be pressed firmly against the projectile body 2, whereby a dependable transmission to the projectile body is assured.

We claim:

1. In combination with a fin-stabilized subcaliber projectile having a projectile body with a central portion provided with a multiplicity of formations in the configuration of a screw thread and an end portion provided with stabilizing fins, the improvement which comprises:

a drive cage surrounding said central portion and formed with a plurality of segments configured with internal threads to engage said formations and adapted to spread apart from said body in flight;

a ring surrounding said segments at an end of said cage turned toward said fins for retaining said segments temporarily together and against said body, said cage being formed at said end turned toward said fins and adjacent said ring with a frustoconical portion tapered toward said fins,

a frustoconical sealing disk overlying said frustoconical portion and adapted to apply radially inward force to said segments to retain them against said body upon the application of gas pressure to said disk; and

means for securing said disk to said segments, and including screws threaded into said segments through said disk and having heads outwardly of said disk and respective washers interposed between said screw head and said disk. 

1. In combination with a fin-stabilized subcaliber projectile having a projectile body with a central portion provided with a multiplicity of formations in the configuration of a screw thread and an end portion provided with stabilizing fins, the improvement which comprises: a drive cage surrounding said central portion and formed with a plurality of segments configured with internal threads to engage said formations and adapted to spread apart from said body in flight; a ring surrounding said segments at an end of said cage turned toward said fins for retaining said segments temporarily together and against said body, said cage being formed at said end turned toward said fins and adjacent said ring with a frustoconical portion tapered toward said fins, a frustoconical sealing disk overlying said frustoconical portion and adapted to apply radially inward force to said segments to retain them against said body upon the application of gas pressure to said disk; and means for securing said disk to said segments, and including screws threaded into said segments through said disk and having heads outwardly of said disk and respective washers interposed between said screw head and said disk. 